Effects of\nMoisture Content on the Radiative Properties\nand Energy-Saving Performance of Silica Aerogel Windows

The thermal insulation performance of windows is crucial\nfor energy-efficient\nbuildings. Windows are typically the weakest part of the building\nenvelope, regarding thermal insulation. Due to its excellent thermal\ninsulation and high transparency, silica aerogel shows great promise\nas a window material. However, moisture can impact the effectiveness\nof the aerogel, leading to poor visibility and reduced thermal insulation.\nThis study simulated a silica aerogel with varying moisture levels\nusing the combination of diffusion-limited cluster aggregation, discrete\ndipole approximation, and Monte Carlo methods. The effects of the\nmoisture content, thickness, porosity, and particle size on thermal\nconductivity, solar transmittance, and haze were analyzed. Visual\nproperties of the aerogels were also considered. The energy consumption\nof a 30 m<sup>2</sup> room under different climates was simulated\nusing TRNSYS to assess the energy-saving potential of silica aerogel\nglass. The findings indicate that a higher moisture content leads\nto decreased solar transmittance and increased thermal conductivity\nof aerogels. Silica aerogel glass is more energy efficient than single-layer\nfloat glass, with the dry aerogel performing better in cold climates\nbut worse in hot climates. This study provides insights for designing\naerogel glass that optimizes solar transmittance and thermal insulation\nto enhance building comfort and energy efficiency.